FIELD OF THE INVENTION
Principal uses of sulphuric acid are in the manufacture of fertilizers and in water treatment.
Sulphuric acid (H.sub.2 SO.sub.4) is one of the most important "Heavy Chemicals", that is, marketed by the ton.
Sulphuric acid has been commercially produced since about 1730; when it was used principally for medicinal purposes. In 1749 the "Glass Bulb" method of pounds of production was changed to the improved "Lead Chamber" process for tons of production per day.
Currently two production methods are in common use. The first known as the "Lead Chamber", being an improved (18th) Eighteenth Century method. In this process sulphur is burned to produce sulphur dioxide, and then in the presence of a catalyst, further oxidized to sulphur tri-oxide which in the presence of water forms sulphuric acid. The second process is known as the "Contact" process; which involves the oxidation of sulphur dioxide with air or oxygen at high temperatures in contact with a solid catalyst followed by mixing the sulphur tri-oxide with sufficient water to produce the strength of acid desired.